I built Disney's" Man in Space" when I was in the sith grade.
IIFC, the Main "booster" had something like 24 "engine" nozzles, and 16 for the next stage.

The old X15 plastic kit lent itself to PMC. Had to use rear ejection. Flew ok, recovery kind of, ummm, well, was haphazard. I hadn't perfected rear ejection recovery back then I still don't mess with it. IIRC, the body tube that fit in there perfectly was a BT30.

Those kits brought back some fond memories. Thanks again for the link.